Tax exemption is not a status a charity receives once; it is a continuing bargain with terms, and the terms are about where the money goes. This article explains the three overlapping regimes that police value flowing out of a charity to the people who control it: the absolute prohibition on private inurement, the more flexible but broader private benefit doctrine that reaches strangers as well as insiders, and the section 4958 excise taxes that let the IRS punish an abusive transaction without destroying the organization. It works through the rebuttable presumption of reasonableness and the three procedural steps that create it, the automatic excess benefit rule that turns an unreported cell phone allowance into a taxable event, and the far harsher strict liability regime that governs private foundations under section 4941. It then turns to the state law duties of care, loyalty, and obedience that run alongside the federal tax rules, the role of the attorney general as the party who actually sues, and the structural settings — joint ventures, taxable subsidiaries, and management contracts — where private benefit is built into the architecture rather than voted on at a meeting. A fictional youth music charity carries the analysis from a compensation vote to a rehearsal hall joint venture.